Underestimating Google can be disastrous, says Don Reisinger on CNET recently, especially if you are a mobile carrier. I’ve been saying this for a while too but I’d like to play devil’s advocate for a minute and suggest that overestimating Google can lead to a waste of money and focus even if it isn’t disastrous. You can also think of this as suggesting that while only the paranoid can survive, the excessively paranoid may not survive either.

Google has one main reason for moving outside of its core area of expertise in advertising: it wants to put lots of advertising in lots of places and wants those places to get lots of eyeballs. When it sees industries standing in the way of that it has an incentive to go in and flatten them so that it can achieve its business objective of (Google) advertising everywhere all the time. That’s why the mobile carriers that have moved glacially to opening up their networks to stimulating applications and traffics are like a moose looking down Sarah Palin’s rifle. But while Google is pretty scary it hasn’t really demonstrated huge success outside of what it is really good at—search-based advertising. It hasn’t taken the advertising world by storm—yet—in display ads or its other initiatives to get into off-line adds; Google Checkout isn’t exactly killing PayPal; Google Video went bust; the MySpace deal was probably a waste; and the list goes on.

Making a ton of money on a hit product can hide a lot of sins and there’s a case to be made that Google isn’t necessarily very good outside of that hit product. Maybe Android will succeed but with this track record one can’t be sure. Those in Google’s line of site should worry but they shouldn’t let it distract them from other perhaps more serious business risks. I think the moderately paranoid survive.